This invention relates to a time-measuring and indicating apparatus, and to a system and method for measuring, recording and comparing the elapsed time required to complete an event or function for each of a plurality of moving entities.
U.S. Pat. No. 4,142,680 describes a system for indicating the elapsed time from a start point of each of a plurality of entities, such as race horses, to the end of the course. A plurality of radio frequency transmitters, each carried by respective entities, emanate a radio frequency signal discrete to that entity. A timing counter receives the signals, and by the particular frequency received identifies the entity and transmits the information to be printed out for obtaining the times of the racing entities.
U.S. Pat. No. 3,434,712 teaches a timing apparatus having a timing portion which is connected to an indicating portion which can be a display. The display can be connected to a printer/recorder for printing out information.
U.S. Pat. No. 4,245,334 teaches a self-contained device for measuring and indicating the time between the reception of first and second airborne signals. This device carries a timer and display on a single unit and is designed to indicate elapsed time to a single entity as directly as possible.
The only device discussed above designed to indicate elapsed time from the beginning of an event to the end of the event to a plurality of entities is U.S. Pat. No. 4,142,680. This system, however, has a number of disadvantages in that it is very complicated and difficult to operate. Moreover, the number of entities is limited by the presently limited number of frequencies which can be employed and serious problems are presented, especially when timing from one specific location to another location.
On the other hand, U.S. Pat. No. 4,245,334 teaches a simple unit for timing an event of a single entity and displaying elapsed time directly to the entity. However, it is impossible to adapt this device to timing a plurality of entities simultaneously.